progs/tests/getteximage.c

   1 /**
   2  * Test glGetTexImage()
   3  * Brian Paul
   4  * 9 June 2009
   5  */
   6
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <math.h>
  11 #include <GL/glew.h>
  12 #include <GL/glut.h>
  13
  14 static int Win;
  15
  16
  17 static void
  18 TestGetTexImage(GLboolean npot)
  19 {
  20    GLuint iter;
  21    GLubyte *data = (GLubyte *) malloc(1024 * 1024 * 4);
  22    GLubyte *data2 = (GLubyte *) malloc(1024 * 1024 * 4);
  23
  24    glEnable(GL_TEXTURE_2D);
  25
  26    printf("glTexImage2D + glGetTexImage:\n");
  27
  28    for (iter = 0; iter < 8; iter++) {
  29       GLint p = (iter % 8) + 3;
  30       GLint w = npot ? (p * 20) : (1 << p);
  31       GLint h = npot ? (p * 10) : (1 << p);
  32       GLuint i;
  33       GLint level = 0;
  34
  35       printf("  Testing %d x %d tex image\n", w, h);
  36
  37       /* fill data */
  38       for (i = 0; i < w * h * 4; i++) {
  39          data[i] = i & 0xff;
  40          data2[i] = 0;
  41       }
  42
  43       glTexImage2D(GL_TEXTURE_2D, level, GL_RGBA, w, h, 0,
  44                    GL_RGBA, GL_UNSIGNED_BYTE, data);
  45
  46       glBegin(GL_POINTS);
  47       glVertex2f(0, 0);
  48       glEnd();
  49
  50       /* get */
  51       glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
  52
  53       /* compare */
  54       for (i = 0; i < w * h * 4; i++) {
  55          if (data2[i] != data[i]) {
  56             printf("glTexImage + glGetTexImage failure!\n");
  57             printf("Expected value %d, found %d\n", data[i], data2[i]);
  58             abort();
  59          }
  60       }
  61    }
  62
  63    printf("Passed\n");
  64    glDisable(GL_TEXTURE_2D);
  65    free(data);
  66    free(data2);
  67 }
  68
  69
  70 static GLboolean
  71 ColorsEqual(const GLubyte ref[4], const GLubyte act[4])
  72 {
  73    if (abs((int) ref[0] - (int) act[0]) > 1 ||
  74        abs((int) ref[1] - (int) act[1]) > 1 ||
  75        abs((int) ref[2] - (int) act[2]) > 1 ||
  76        abs((int) ref[3] - (int) act[3]) > 1) {
  77       printf("expected %d %d %d %d\n", ref[0], ref[1], ref[2], ref[3]);
  78       printf("found    %d %d %d %d\n", act[0], act[1], act[2], act[3]);
  79       return GL_FALSE;
  80    }
  81    return GL_TRUE;
  82 }
  83
  84
  85 static void
  86 TestGetTexImageRTT(GLboolean npot)
  87 {
  88    GLuint iter;
  89
  90    printf("Render to texture + glGetTexImage:\n");
  91
  92    for (iter = 0; iter < 8; iter++) {
  93
  94       GLuint fb, tex;
  95       GLint w, h;
  96       GLint level = 0;
  97
  98       if (npot) {
  99          w = 200 + iter * 40;
 100          h = 200 + iter * 12;
 101       }
 102       else {
 103          w = 4 << iter;
 104          h = 4 << iter;
 105       }
 106
 107       glGenTextures(1, &tex);
 108       glGenFramebuffersEXT(1, &fb);
 109
 110       glBindTexture(GL_TEXTURE_2D, tex);
 111       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 112       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 113       glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0,
 114                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 115
 116       glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
 117       glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 118                                 GL_TEXTURE_2D, tex, level);
 119
 120       glViewport(0, 0, w, h);
 121
 122       printf("  Testing %d x %d tex image\n", w, h);
 123       {
 124          static const GLubyte blue[4] = {0, 0, 255, 255};
 125          GLubyte color[4];
 126          GLubyte *data2 = (GLubyte *) malloc(w * h * 4);
 127          GLuint i;
 128
 129          /* random clear color */
 130          for (i = 0; i < 4; i++) {
 131             color[i] = rand() % 256;
 132          }
 133
 134          glClearColor(color[0] / 255.0,
 135                       color[1] / 255.0,
 136                       color[2] / 255.0,
 137                       color[3] / 255.0);
 138
 139          glClear(GL_COLOR_BUFFER_BIT);
 140
 141          /* draw polygon over top half, in blue */
 142          glColor4ubv(blue);
 143          glRectf(0, 0.5, 1.0, 1.0);
 144
 145          /* get */
 146          glGetTexImage(GL_TEXTURE_2D, level, GL_RGBA, GL_UNSIGNED_BYTE, data2);
 147
 148          /* compare */
 149          for (i = 0; i < w * h; i += 4) {
 150             if (i < w * h / 2) {
 151                /* lower half */
 152                if (!ColorsEqual(color, data2 + i * 4)) {
 153                   printf("Render to texture failure (expected clear color)!\n");
 154                   abort();
 155                }
 156             }
 157             else {
 158                /* upper half */
 159                if (!ColorsEqual(blue, data2 + i * 4)) {
 160                   printf("Render to texture failure (expected blue)!\n");
 161                   abort();
 162                }
 163             }
 164          }
 165
 166          free(data2);
 167       }
 168
 169       glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 170       glDeleteFramebuffersEXT(1, &fb);
 171       glDeleteTextures(1, &tex);
 172
 173    }
 174
 175    printf("Passed\n");
 176 }
 177
 178
 179
 180
 181 static void
 182 Draw(void)
 183 {
 184    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 185
 186    TestGetTexImage(GL_FALSE);
 187    if (glutExtensionSupported("GL_ARB_texture_non_power_of_two"))
 188       TestGetTexImage(GL_TRUE);
 189
 190    if (glutExtensionSupported("GL_EXT_framebuffer_object") ||
 191        glutExtensionSupported("GL_ARB_framebuffer_object")) {
 192       TestGetTexImageRTT(GL_FALSE);
 193       if (glutExtensionSupported("GL_ARB_texture_non_power_of_two"))
 194          TestGetTexImageRTT(GL_TRUE);
 195    }
 196
 197    glutDestroyWindow(Win);
 198    exit(0);
 199
 200    glutSwapBuffers();
 201 }
 202
 203
 204 static void
 205 Reshape(int width, int height)
 206 {
 207    glViewport(0, 0, width, height);
 208    glMatrixMode(GL_PROJECTION);
 209    glLoadIdentity();
 210    glOrtho(0, 1, 0, 1, -1, 1);
 211    glMatrixMode(GL_MODELVIEW);
 212    glLoadIdentity();
 213    glTranslatef(0.0, 0.0, 0.0);
 214 }
 215
 216
 217 static void
 218 Key(unsigned char key, int x, int y)
 219 {
 220    (void) x;
 221    (void) y;
 222    switch (key) {
 223       case 27:
 224          glutDestroyWindow(Win);
 225          exit(0);
 226          break;
 227    }
 228    glutPostRedisplay();
 229 }
 230
 231
 232 static void
 233 Init(void)
 234 {
 235 }
 236
 237
 238 int
 239 main(int argc, char *argv[])
 240 {
 241    glutInit(&argc, argv);
 242    glutInitWindowPosition(0, 0);
 243    glutInitWindowSize(400, 400);
 244    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 245    Win = glutCreateWindow(argv[0]);
 246    glewInit();
 247    glutReshapeFunc(Reshape);
 248    glutKeyboardFunc(Key);
 249    glutDisplayFunc(Draw);
 250    Init();
 251    glutMainLoop();
 252    return 0;
 253 }